{feature} add isOpen variant to screen types

This makes it easier to write tests that span multiple pages,
for example

```ts
class ScreenOne extends ComponentHarness {
	static path = '/one';

	#next = this.locatorFor('#next');

	async goToNext() {
		await (await this.next()).click();
	}
}

class ScreenTwo extends ComponentHarness {
	static async isOpen(page) {
	  return page.url().endsWith('/two');
	}
}

test('navigation', ({open}) => {
  const screenOne = await open(ScreenOne);

  await screenOne.goToNext();

  const screenTwo = await open(ScreenTwo);

  // ...
});
```

Screens with a path or open function can also define an
isOpen function. If that function is present and it yields
a truthy result, then the open function will not be called
or no navigation will be triggered to the path.

.yarn/versions/c84ee467.yml

@@ -0,0 +1,2 @@
+releases:
+  "@ngx-playwright/test": patch

packages/test/src/screen.js

@@ -32,12 +32,19 @@ export async function openScreen(baseURL, page, harnessEnvironment, screen) {
 		);
 	}
 
-	if (hasOpenFunction(screen)) {
-		await screen.open(page, baseURL, (screen) =>
-			openScreen(baseURL, page, harnessEnvironment, screen),
-		);
-	} else {
-		await page.goto(new URL(screen.path, baseURL).href);
+	if (
+		typeof screen.isOpen !== "function" ||
+		!(await screen.isOpen(page, baseURL))
+	) {
+		if (hasOpenFunction(screen)) {
+			await screen.open(page, baseURL, (screen) =>
+				openScreen(baseURL, page, harnessEnvironment, screen),
+			);
+		} else if ("path" in screen && typeof screen.path === "string") {
+			await page.goto(new URL(screen.path, baseURL).href);
+		} else {
+			throw new Error("Expected screen to be open but it wasn't");
+		}
 	}
 
 	return harnessEnvironment.getHarness(screen);

packages/test/src/types.d.ts

@@ -8,6 +8,8 @@ import {Page} from "@playwright/test";
 export interface PlaywrightScreenWithPath<T extends AnyComponentHarness>
 	extends ComponentHarnessConstructor<T> {
 	readonly path: string;
+
+	isOpen?(page: Page, baseUrl: string): Promise<boolean>;
 }
 
 export interface PlaywrightScreenWithOpenFunction<T extends AnyComponentHarness>
@@ -17,11 +19,20 @@ export interface PlaywrightScreenWithOpenFunction<T extends AnyComponentHarness>
 		baseUrl: string,
 		opener: PlaywrightScreenOpener,
 	): Promise<void>;
+
+	isOpen?(page: Page, baseUrl: string): Promise<boolean>;
+}
+
+export interface PlaywrightScreenWithIsOpenFunction<
+	T extends AnyComponentHarness,
+> extends ComponentHarnessConstructor<T> {
+	isOpen(page: Page, baseUrl: string): Promise<boolean>;
 }
 
 export type PlaywrightScreen<T extends AnyComponentHarness> =
 	| PlaywrightScreenWithOpenFunction<T>
-	| PlaywrightScreenWithPath<T>;
+	| PlaywrightScreenWithPath<T>
+	| PlaywrightScreenWithIsOpenFunction<T>;
 
 export interface PlaywrightScreenOpener {
 	<T extends AnyComponentHarness>(screen: PlaywrightScreen<T>): Promise<T>;